Cataracts in Dogs & Cats: Signs, Causes & Surgery
Cloudy eyes in your pet may signal cataracts, a leading cause of blindness. Early detection and treatment can restore vision.
A cataract is the clouding of the lens inside the eye, which prevents light from reaching the retina. Cataracts are the most common cause of blindness in dogs and can develop rapidly or slowly depending on the cause.
Key Points
- Cataracts cause the pupil to appear cloudy, white, or bluish-gray
- Diabetes is a major cause of rapid cataract formation in dogs
- Inherited cataracts are common in breeds like Cocker Spaniels, Poodles, and Huskies
- Surgical removal by a veterinary ophthalmologist can restore vision
- Untreated cataracts may lead to painful secondary glaucoma
- Not all cloudiness is cataracts — nuclear sclerosis is a normal aging change
Understanding Cataracts
The lens is normally clear and focuses light on the retina. When proteins in the lens break down, they clump together causing cloudiness. Cataracts can affect part or all of the lens. Incipient cataracts are small; immature cataracts cover more of the lens but vision remains. Mature cataracts cause complete blindness. Hypermature cataracts can shrink and cause lens instability.
Causes in Pets
Hereditary cataracts are the most common cause in dogs, affecting breeds like Cocker Spaniels, Poodles, Boston Terriers, and Golden Retrievers. Diabetes mellitus causes rapid bilateral cataracts due to sorbitol accumulation. Trauma, uveitis, and retinal degeneration can also cause cataracts. Age-related cataracts develop slowly in older pets. Congenital cataracts are present at birth.
Diagnosis & Staging
Your veterinarian uses an ophthalmoscope to examine the lens. Blood tests check for diabetes and metabolic disease. A veterinary ophthalmologist performs ERG (electroretinography) to ensure the retina is healthy before surgery. Ultrasound evaluates the back of the eye if the cataract is too dense to see through. IOP (intraocular pressure) testing checks for glaucoma.
Treatment Options
The only effective treatment is phacoemulsification — ultrasound-assisted lens removal performed by a veterinary ophthalmologist. An artificial intraocular lens (IOL) is often implanted to restore focusing ability. Without surgery, topical anti-inflammatory drops help prevent complications. Cataracts caused by diabetes may stabilize if blood sugar is controlled. Surgery has an 85-95% success rate in uncomplicated cases.
When to See a Vet Immediately
- You notice cloudiness or a milky appearance in your pet's eyes
- Your pet is bumping into furniture or seems hesitant in dim light
- The pupil appears white instead of black
- Your pet is a diabetic with rapidly changing vision
- The eye appears painful or red
How RVC Can Help
This article is for educational purposes only and does not replace professional veterinary advice. If your pet is showing any symptoms, please contact Royal Veterinary Center immediately at +853 6677 6611.